aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/cpuidle
diff options
context:
space:
mode:
Diffstat (limited to 'drivers/cpuidle')
-rw-r--r--drivers/cpuidle/Kconfig.arm27
-rw-r--r--drivers/cpuidle/Makefile3
-rw-r--r--drivers/cpuidle/coupled.c2
-rw-r--r--drivers/cpuidle/cpuidle-at91.c69
-rw-r--r--drivers/cpuidle/cpuidle-calxeda.c61
-rw-r--r--drivers/cpuidle/cpuidle-ux500.c2
-rw-r--r--drivers/cpuidle/cpuidle-zynq.c17
-rw-r--r--drivers/cpuidle/cpuidle.c80
-rw-r--r--drivers/cpuidle/driver.c67
-rw-r--r--drivers/cpuidle/governor.c43
-rw-r--r--drivers/cpuidle/sysfs.c7
11 files changed, 194 insertions, 184 deletions
diff --git a/drivers/cpuidle/Kconfig.arm b/drivers/cpuidle/Kconfig.arm
index 8e3660322308..d988948a89a0 100644
--- a/drivers/cpuidle/Kconfig.arm
+++ b/drivers/cpuidle/Kconfig.arm
@@ -2,9 +2,20 @@
# ARM CPU Idle drivers
#
+config ARM_BIG_LITTLE_CPUIDLE
+ bool "Support for ARM big.LITTLE processors"
+ depends on ARCH_VEXPRESS_TC2_PM
+ select ARM_CPU_SUSPEND
+ select CPU_IDLE_MULTIPLE_DRIVERS
+ help
+ Select this option to enable CPU idle driver for big.LITTLE based
+ ARM systems. Driver manages CPUs coordination through MCPM and
+ define different C-states for little and big cores through the
+ multiple CPU idle drivers infrastructure.
+
config ARM_HIGHBANK_CPUIDLE
bool "CPU Idle Driver for Calxeda processors"
- depends on ARCH_HIGHBANK
+ depends on ARM_PSCI
select ARM_CPU_SUSPEND
help
Select this to enable cpuidle on Calxeda processors.
@@ -27,13 +38,9 @@ config ARM_U8500_CPUIDLE
help
Select this to enable cpuidle for ST-E u8500 processors
-config CPU_IDLE_BIG_LITTLE
- bool "Support for ARM big.LITTLE processors"
- depends on ARCH_VEXPRESS_TC2_PM
- select ARM_CPU_SUSPEND
- select CPU_IDLE_MULTIPLE_DRIVERS
+config ARM_AT91_CPUIDLE
+ bool "Cpu Idle Driver for the AT91 processors"
+ default y
+ depends on ARCH_AT91
help
- Select this option to enable CPU idle driver for big.LITTLE based
- ARM systems. Driver manages CPUs coordination through MCPM and
- define different C-states for little and big cores through the
- multiple CPU idle drivers infrastructure.
+ Select this to enable cpuidle for AT91 processors
diff --git a/drivers/cpuidle/Makefile b/drivers/cpuidle/Makefile
index cea5ef58876d..527be28e5c1e 100644
--- a/drivers/cpuidle/Makefile
+++ b/drivers/cpuidle/Makefile
@@ -7,8 +7,9 @@ obj-$(CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED) += coupled.o
##################################################################################
# ARM SoC drivers
+obj-$(CONFIG_ARM_BIG_LITTLE_CPUIDLE) += cpuidle-big_little.o
obj-$(CONFIG_ARM_HIGHBANK_CPUIDLE) += cpuidle-calxeda.o
obj-$(CONFIG_ARM_KIRKWOOD_CPUIDLE) += cpuidle-kirkwood.o
obj-$(CONFIG_ARM_ZYNQ_CPUIDLE) += cpuidle-zynq.o
obj-$(CONFIG_ARM_U8500_CPUIDLE) += cpuidle-ux500.o
-obj-$(CONFIG_CPU_IDLE_BIG_LITTLE) += cpuidle-big_little.o
+obj-$(CONFIG_ARM_AT91_CPUIDLE) += cpuidle-at91.o
diff --git a/drivers/cpuidle/coupled.c b/drivers/cpuidle/coupled.c
index f8a86364c6b6..e952936418d0 100644
--- a/drivers/cpuidle/coupled.c
+++ b/drivers/cpuidle/coupled.c
@@ -147,7 +147,7 @@ static cpumask_t cpuidle_coupled_poked;
* has returned from this function, the barrier is immediately available for
* reuse.
*
- * The atomic variable a must be initialized to 0 before any cpu calls
+ * The atomic variable must be initialized to 0 before any cpu calls
* this function, will be reset to 0 before any cpu returns from this function.
*
* Must only be called from within a coupled idle state handler
diff --git a/drivers/cpuidle/cpuidle-at91.c b/drivers/cpuidle/cpuidle-at91.c
new file mode 100644
index 000000000000..a0774370c6bc
--- /dev/null
+++ b/drivers/cpuidle/cpuidle-at91.c
@@ -0,0 +1,69 @@
+/*
+ * based on arch/arm/mach-kirkwood/cpuidle.c
+ *
+ * CPU idle support for AT91 SoC
+ *
+ * This file is licensed under the terms of the GNU General Public
+ * License version 2. This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ *
+ * The cpu idle uses wait-for-interrupt and RAM self refresh in order
+ * to implement two idle states -
+ * #1 wait-for-interrupt
+ * #2 wait-for-interrupt and RAM self refresh
+ */
+
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/platform_device.h>
+#include <linux/cpuidle.h>
+#include <linux/io.h>
+#include <linux/export.h>
+#include <asm/proc-fns.h>
+#include <asm/cpuidle.h>
+
+#define AT91_MAX_STATES 2
+
+static void (*at91_standby)(void);
+
+/* Actual code that puts the SoC in different idle states */
+static int at91_enter_idle(struct cpuidle_device *dev,
+ struct cpuidle_driver *drv,
+ int index)
+{
+ at91_standby();
+ return index;
+}
+
+static struct cpuidle_driver at91_idle_driver = {
+ .name = "at91_idle",
+ .owner = THIS_MODULE,
+ .states[0] = ARM_CPUIDLE_WFI_STATE,
+ .states[1] = {
+ .enter = at91_enter_idle,
+ .exit_latency = 10,
+ .target_residency = 10000,
+ .flags = CPUIDLE_FLAG_TIME_VALID,
+ .name = "RAM_SR",
+ .desc = "WFI and DDR Self Refresh",
+ },
+ .state_count = AT91_MAX_STATES,
+};
+
+/* Initialize CPU idle by registering the idle states */
+static int at91_cpuidle_probe(struct platform_device *dev)
+{
+ at91_standby = (void *)(dev->dev.platform_data);
+
+ return cpuidle_register(&at91_idle_driver, NULL);
+}
+
+static struct platform_driver at91_cpuidle_driver = {
+ .driver = {
+ .name = "cpuidle-at91",
+ .owner = THIS_MODULE,
+ },
+ .probe = at91_cpuidle_probe,
+};
+
+module_platform_driver(at91_cpuidle_driver);
diff --git a/drivers/cpuidle/cpuidle-calxeda.c b/drivers/cpuidle/cpuidle-calxeda.c
index 346058479572..6e51114057d0 100644
--- a/drivers/cpuidle/cpuidle-calxeda.c
+++ b/drivers/cpuidle/cpuidle-calxeda.c
@@ -21,53 +21,30 @@
*/
#include <linux/cpuidle.h>
+#include <linux/cpu_pm.h>
#include <linux/init.h>
-#include <linux/io.h>
-#include <linux/of.h>
-#include <linux/time.h>
-#include <linux/delay.h>
-#include <linux/suspend.h>
+#include <linux/mm.h>
+#include <linux/platform_device.h>
#include <asm/cpuidle.h>
-#include <asm/proc-fns.h>
-#include <asm/smp_scu.h>
#include <asm/suspend.h>
-#include <asm/cacheflush.h>
-#include <asm/cp15.h>
-
-extern void highbank_set_cpu_jump(int cpu, void *jump_addr);
-extern void __iomem *scu_base_addr;
-
-static noinline void calxeda_idle_restore(void)
-{
- set_cr(get_cr() | CR_C);
- set_auxcr(get_auxcr() | 0x40);
- scu_power_mode(scu_base_addr, SCU_PM_NORMAL);
-}
+#include <asm/psci.h>
static int calxeda_idle_finish(unsigned long val)
{
- /* Already flushed cache, but do it again as the outer cache functions
- * dirty the cache with spinlocks */
- flush_cache_all();
-
- set_auxcr(get_auxcr() & ~0x40);
- set_cr(get_cr() & ~CR_C);
-
- scu_power_mode(scu_base_addr, SCU_PM_DORMANT);
-
- cpu_do_idle();
-
- /* Restore things if we didn't enter power-gating */
- calxeda_idle_restore();
- return 1;
+ const struct psci_power_state ps = {
+ .type = PSCI_POWER_STATE_TYPE_POWER_DOWN,
+ };
+ return psci_ops.cpu_suspend(ps, __pa(cpu_resume));
}
static int calxeda_pwrdown_idle(struct cpuidle_device *dev,
struct cpuidle_driver *drv,
int index)
{
- highbank_set_cpu_jump(smp_processor_id(), cpu_resume);
+ cpu_pm_enter();
cpu_suspend(0, calxeda_idle_finish);
+ cpu_pm_exit();
+
return index;
}
@@ -88,11 +65,17 @@ static struct cpuidle_driver calxeda_idle_driver = {
.state_count = 2,
};
-static int __init calxeda_cpuidle_init(void)
+static int calxeda_cpuidle_probe(struct platform_device *pdev)
{
- if (!of_machine_is_compatible("calxeda,highbank"))
- return -ENODEV;
-
return cpuidle_register(&calxeda_idle_driver, NULL);
}
-module_init(calxeda_cpuidle_init);
+
+static struct platform_driver calxeda_cpuidle_plat_driver = {
+ .driver = {
+ .name = "cpuidle-calxeda",
+ .owner = THIS_MODULE,
+ },
+ .probe = calxeda_cpuidle_probe,
+};
+
+module_platform_driver(calxeda_cpuidle_plat_driver);
diff --git a/drivers/cpuidle/cpuidle-ux500.c b/drivers/cpuidle/cpuidle-ux500.c
index e0564652af35..5e35804b1a95 100644
--- a/drivers/cpuidle/cpuidle-ux500.c
+++ b/drivers/cpuidle/cpuidle-ux500.c
@@ -111,7 +111,7 @@ static struct cpuidle_driver ux500_idle_driver = {
.state_count = 2,
};
-static int __init dbx500_cpuidle_probe(struct platform_device *pdev)
+static int dbx500_cpuidle_probe(struct platform_device *pdev)
{
/* Configure wake up reasons */
prcmu_enable_wakeups(PRCMU_WAKEUP(ARM) | PRCMU_WAKEUP(RTC) |
diff --git a/drivers/cpuidle/cpuidle-zynq.c b/drivers/cpuidle/cpuidle-zynq.c
index 38e03a183591..aded75928028 100644
--- a/drivers/cpuidle/cpuidle-zynq.c
+++ b/drivers/cpuidle/cpuidle-zynq.c
@@ -28,7 +28,7 @@
#include <linux/init.h>
#include <linux/cpu_pm.h>
#include <linux/cpuidle.h>
-#include <linux/of.h>
+#include <linux/platform_device.h>
#include <asm/proc-fns.h>
#include <asm/cpuidle.h>
@@ -70,14 +70,19 @@ static struct cpuidle_driver zynq_idle_driver = {
};
/* Initialize CPU idle by registering the idle states */
-static int __init zynq_cpuidle_init(void)
+static int zynq_cpuidle_probe(struct platform_device *pdev)
{
- if (!of_machine_is_compatible("xlnx,zynq-7000"))
- return -ENODEV;
-
pr_info("Xilinx Zynq CpuIdle Driver started\n");
return cpuidle_register(&zynq_idle_driver, NULL);
}
-device_initcall(zynq_cpuidle_init);
+static struct platform_driver zynq_cpuidle_driver = {
+ .driver = {
+ .name = "cpuidle-zynq",
+ .owner = THIS_MODULE,
+ },
+ .probe = zynq_cpuidle_probe,
+};
+
+module_platform_driver(zynq_cpuidle_driver);
diff --git a/drivers/cpuidle/cpuidle.c b/drivers/cpuidle/cpuidle.c
index d75040ddd2b3..a55e68f2cfc8 100644
--- a/drivers/cpuidle/cpuidle.c
+++ b/drivers/cpuidle/cpuidle.c
@@ -118,11 +118,9 @@ int cpuidle_idle_call(void)
struct cpuidle_device *dev = __this_cpu_read(cpuidle_devices);
struct cpuidle_driver *drv;
int next_state, entered_state;
+ bool broadcast;
- if (off)
- return -ENODEV;
-
- if (!initialized)
+ if (off || !initialized)
return -ENODEV;
/* check if the device is ready */
@@ -144,9 +142,10 @@ int cpuidle_idle_call(void)
trace_cpu_idle_rcuidle(next_state, dev->cpu);
- if (drv->states[next_state].flags & CPUIDLE_FLAG_TIMER_STOP)
- clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_ENTER,
- &dev->cpu);
+ broadcast = !!(drv->states[next_state].flags & CPUIDLE_FLAG_TIMER_STOP);
+
+ if (broadcast)
+ clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_ENTER, &dev->cpu);
if (cpuidle_state_is_coupled(dev, drv, next_state))
entered_state = cpuidle_enter_state_coupled(dev, drv,
@@ -154,9 +153,8 @@ int cpuidle_idle_call(void)
else
entered_state = cpuidle_enter_state(dev, drv, next_state);
- if (drv->states[next_state].flags & CPUIDLE_FLAG_TIMER_STOP)
- clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_EXIT,
- &dev->cpu);
+ if (broadcast)
+ clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_EXIT, &dev->cpu);
trace_cpu_idle_rcuidle(PWR_EVENT_EXIT, dev->cpu);
@@ -228,45 +226,6 @@ void cpuidle_resume(void)
mutex_unlock(&cpuidle_lock);
}
-#ifdef CONFIG_ARCH_HAS_CPU_RELAX
-static int poll_idle(struct cpuidle_device *dev,
- struct cpuidle_driver *drv, int index)
-{
- ktime_t t1, t2;
- s64 diff;
-
- t1 = ktime_get();
- local_irq_enable();
- while (!need_resched())
- cpu_relax();
-
- t2 = ktime_get();
- diff = ktime_to_us(ktime_sub(t2, t1));
- if (diff > INT_MAX)
- diff = INT_MAX;
-
- dev->last_residency = (int) diff;
-
- return index;
-}
-
-static void poll_idle_init(struct cpuidle_driver *drv)
-{
- struct cpuidle_state *state = &drv->states[0];
-
- snprintf(state->name, CPUIDLE_NAME_LEN, "POLL");
- snprintf(state->desc, CPUIDLE_DESC_LEN, "CPUIDLE CORE POLL IDLE");
- state->exit_latency = 0;
- state->target_residency = 0;
- state->power_usage = -1;
- state->flags = 0;
- state->enter = poll_idle;
- state->disabled = false;
-}
-#else
-static void poll_idle_init(struct cpuidle_driver *drv) {}
-#endif /* CONFIG_ARCH_HAS_CPU_RELAX */
-
/**
* cpuidle_enable_device - enables idle PM for a CPU
* @dev: the CPU
@@ -296,8 +255,6 @@ int cpuidle_enable_device(struct cpuidle_device *dev)
if (!dev->state_count)
dev->state_count = drv->state_count;
- poll_idle_init(drv);
-
ret = cpuidle_add_device_sysfs(dev);
if (ret)
return ret;
@@ -358,12 +315,10 @@ static void __cpuidle_unregister_device(struct cpuidle_device *dev)
module_put(drv->owner);
}
-static int __cpuidle_device_init(struct cpuidle_device *dev)
+static void __cpuidle_device_init(struct cpuidle_device *dev)
{
memset(dev->states_usage, 0, sizeof(dev->states_usage));
dev->last_residency = 0;
-
- return 0;
}
/**
@@ -385,13 +340,12 @@ static int __cpuidle_register_device(struct cpuidle_device *dev)
list_add(&dev->device_list, &cpuidle_detected_devices);
ret = cpuidle_coupled_register_device(dev);
- if (ret) {
+ if (ret)
__cpuidle_unregister_device(dev);
- return ret;
- }
+ else
+ dev->registered = 1;
- dev->registered = 1;
- return 0;
+ return ret;
}
/**
@@ -410,9 +364,7 @@ int cpuidle_register_device(struct cpuidle_device *dev)
if (dev->registered)
goto out_unlock;
- ret = __cpuidle_device_init(dev);
- if (ret)
- goto out_unlock;
+ __cpuidle_device_init(dev);
ret = __cpuidle_register_device(dev);
if (ret)
@@ -448,7 +400,7 @@ EXPORT_SYMBOL_GPL(cpuidle_register_device);
*/
void cpuidle_unregister_device(struct cpuidle_device *dev)
{
- if (dev->registered == 0)
+ if (!dev || dev->registered == 0)
return;
cpuidle_pause_and_lock();
@@ -516,7 +468,7 @@ int cpuidle_register(struct cpuidle_driver *drv,
#ifdef CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED
/*
- * On multiplatform for ARM, the coupled idle states could
+ * On multiplatform for ARM, the coupled idle states could be
* enabled in the kernel even if the cpuidle driver does not
* use it. Note, coupled_cpus is a struct copy.
*/
diff --git a/drivers/cpuidle/driver.c b/drivers/cpuidle/driver.c
index 6e11701f0fca..06dbe7c86199 100644
--- a/drivers/cpuidle/driver.c
+++ b/drivers/cpuidle/driver.c
@@ -10,6 +10,7 @@
#include <linux/mutex.h>
#include <linux/module.h>
+#include <linux/sched.h>
#include <linux/cpuidle.h>
#include <linux/cpumask.h>
#include <linux/clockchips.h>
@@ -56,7 +57,7 @@ static inline void __cpuidle_unset_driver(struct cpuidle_driver *drv)
}
/**
- * __cpuidle_set_driver - set per CPU driver variables the the given driver.
+ * __cpuidle_set_driver - set per CPU driver variables for the given driver.
* @drv: a valid pointer to a struct cpuidle_driver
*
* For each CPU in the driver's cpumask, unset the registered driver per CPU
@@ -132,7 +133,7 @@ static inline void __cpuidle_unset_driver(struct cpuidle_driver *drv)
* cpuidle_setup_broadcast_timer - enable/disable the broadcast timer
* @arg: a void pointer used to match the SMP cross call API
*
- * @arg is used as a value of type 'long' with on of the two values:
+ * @arg is used as a value of type 'long' with one of the two values:
* - CLOCK_EVT_NOTIFY_BROADCAST_ON
* - CLOCK_EVT_NOTIFY_BROADCAST_OFF
*
@@ -149,10 +150,8 @@ static void cpuidle_setup_broadcast_timer(void *arg)
/**
* __cpuidle_driver_init - initialize the driver's internal data
* @drv: a valid pointer to a struct cpuidle_driver
- *
- * Returns 0 on success, a negative error code otherwise.
*/
-static int __cpuidle_driver_init(struct cpuidle_driver *drv)
+static void __cpuidle_driver_init(struct cpuidle_driver *drv)
{
int i;
@@ -169,20 +168,55 @@ static int __cpuidle_driver_init(struct cpuidle_driver *drv)
/*
* Look for the timer stop flag in the different states, so that we know
* if the broadcast timer has to be set up. The loop is in the reverse
- * order, because usually on of the the deeper states has this flag set.
+ * order, because usually one of the deeper states have this flag set.
*/
for (i = drv->state_count - 1; i >= 0 ; i--) {
+ if (drv->states[i].flags & CPUIDLE_FLAG_TIMER_STOP) {
+ drv->bctimer = 1;
+ break;
+ }
+ }
+}
- if (!(drv->states[i].flags & CPUIDLE_FLAG_TIMER_STOP))
- continue;
+#ifdef CONFIG_ARCH_HAS_CPU_RELAX
+static int poll_idle(struct cpuidle_device *dev,
+ struct cpuidle_driver *drv, int index)
+{
+ ktime_t t1, t2;
+ s64 diff;
- drv->bctimer = 1;
- break;
- }
+ t1 = ktime_get();
+ local_irq_enable();
+ while (!need_resched())
+ cpu_relax();
- return 0;
+ t2 = ktime_get();
+ diff = ktime_to_us(ktime_sub(t2, t1));
+ if (diff > INT_MAX)
+ diff = INT_MAX;
+
+ dev->last_residency = (int) diff;
+
+ return index;
}
+static void poll_idle_init(struct cpuidle_driver *drv)
+{
+ struct cpuidle_state *state = &drv->states[0];
+
+ snprintf(state->name, CPUIDLE_NAME_LEN, "POLL");
+ snprintf(state->desc, CPUIDLE_DESC_LEN, "CPUIDLE CORE POLL IDLE");
+ state->exit_latency = 0;
+ state->target_residency = 0;
+ state->power_usage = -1;
+ state->flags = 0;
+ state->enter = poll_idle;
+ state->disabled = false;
+}
+#else
+static void poll_idle_init(struct cpuidle_driver *drv) {}
+#endif /* !CONFIG_ARCH_HAS_CPU_RELAX */
+
/**
* __cpuidle_register_driver: register the driver
* @drv: a valid pointer to a struct cpuidle_driver
@@ -206,9 +240,7 @@ static int __cpuidle_register_driver(struct cpuidle_driver *drv)
if (cpuidle_disabled())
return -ENODEV;
- ret = __cpuidle_driver_init(drv);
- if (ret)
- return ret;
+ __cpuidle_driver_init(drv);
ret = __cpuidle_set_driver(drv);
if (ret)
@@ -218,6 +250,8 @@ static int __cpuidle_register_driver(struct cpuidle_driver *drv)
on_each_cpu_mask(drv->cpumask, cpuidle_setup_broadcast_timer,
(void *)CLOCK_EVT_NOTIFY_BROADCAST_ON, 1);
+ poll_idle_init(drv);
+
return 0;
}
@@ -346,10 +380,11 @@ struct cpuidle_driver *cpuidle_driver_ref(void)
*/
void cpuidle_driver_unref(void)
{
- struct cpuidle_driver *drv = cpuidle_get_driver();
+ struct cpuidle_driver *drv;
spin_lock(&cpuidle_driver_lock);
+ drv = cpuidle_get_driver();
if (drv && !WARN_ON(drv->refcnt <= 0))
drv->refcnt--;
diff --git a/drivers/cpuidle/governor.c b/drivers/cpuidle/governor.c
index ea2f8e7aa24a..ca89412f5122 100644
--- a/drivers/cpuidle/governor.c
+++ b/drivers/cpuidle/governor.c
@@ -96,46 +96,3 @@ int cpuidle_register_governor(struct cpuidle_governor *gov)
return ret;
}
-
-/**
- * cpuidle_replace_governor - find a replacement governor
- * @exclude_rating: the rating that will be skipped while looking for
- * new governor.
- */
-static struct cpuidle_governor *cpuidle_replace_governor(int exclude_rating)
-{
- struct cpuidle_governor *gov;
- struct cpuidle_governor *ret_gov = NULL;
- unsigned int max_rating = 0;
-
- list_for_each_entry(gov, &cpuidle_governors, governor_list) {
- if (gov->rating == exclude_rating)
- continue;
- if (gov->rating > max_rating) {
- max_rating = gov->rating;
- ret_gov = gov;
- }
- }
-
- return ret_gov;
-}
-
-/**
- * cpuidle_unregister_governor - unregisters a governor
- * @gov: the governor
- */
-void cpuidle_unregister_governor(struct cpuidle_governor *gov)
-{
- if (!gov)
- return;
-
- mutex_lock(&cpuidle_lock);
- if (gov == cpuidle_curr_governor) {
- struct cpuidle_governor *new_gov;
- new_gov = cpuidle_replace_governor(gov->rating);
- cpuidle_switch_governor(new_gov);
- }
- list_del(&gov->governor_list);
- mutex_unlock(&cpuidle_lock);
-}
-
diff --git a/drivers/cpuidle/sysfs.c b/drivers/cpuidle/sysfs.c
index 8739cc05228c..e918b6d0caf7 100644
--- a/drivers/cpuidle/sysfs.c
+++ b/drivers/cpuidle/sysfs.c
@@ -52,11 +52,12 @@ static ssize_t show_current_driver(struct device *dev,
char *buf)
{
ssize_t ret;
- struct cpuidle_driver *cpuidle_driver = cpuidle_get_driver();
+ struct cpuidle_driver *drv;
spin_lock(&cpuidle_driver_lock);
- if (cpuidle_driver)
- ret = sprintf(buf, "%s\n", cpuidle_driver->name);
+ drv = cpuidle_get_driver();
+ if (drv)
+ ret = sprintf(buf, "%s\n", drv->name);
else
ret = sprintf(buf, "none\n");
spin_unlock(&cpuidle_driver_lock);